class A():
    def __init__(self,name,age):
        self.name = name
        self.age = age

    def __str__(self):
        print(f"name:{self.name},age:{self.age}")

# 如果子类不写构造方法，默认使用父类的构造
class B(A):
    pass

import sys
#b = B()
print(sys.version)